Wireless power transfer apparatus and method thereof

An apparatus comprising:

• a transmitter, including an antenna, wherein the transmitter is configured to transmit power at a multiplicity of frequencies between a first transmission frequency and a second transmission frequency at a first power level;
• and
• a controller configured to measure a signal at each transmission frequency at an antenna of the transmitter and determine whether one or more receiving devices are coupled to the transmitter based on the measured signal by determining if a number of local minima of the measured signal versus frequency is greater than or equal to 2, wherein
• the transmitter is further configured to transmit power at a second power level and at one or more frequencies between the first transmission frequency and the second transmission frequency if the one or more receiving devices are determined to be coupled to the transmitter.

A method comprising:

• transmitting a superposition of a power signal at a first power level at a first frequency with a power signal at a second power level at a second frequency from an antenna of a transmitter, wherein the power signal at the second power level is incremented in transmission frequency from a first value to a second value;
• measuring a time signal indicative of a transmitter-to-receiver coupling criteria at each frequency point;
• separating the measured time signal into a first component and a second component including performing a frequency transform of the measured time signal and isolating a component of the measured time signal corresponding to a frequency band around the second frequency;
• determining whether the second component meets the transmitter-to-receiver coupling criteria;
• and
• transmitting, from the antenna of the transmitter to a receiver, at the first power level and at one or more frequencies between the first frequency and the second frequency if the receiver is determined to be coupled based on the transmitter-to-receiver coupling criteria.

A method comprising:

• transmitting a superposition of a power signal at a first power level at a first frequency with a power signal at a second power level at a second frequency from an antenna of a transmitter, wherein the power signal at the second power level is incremented in transmission frequency from a first value to a second value;
• measuring a time signal indicative of a transmitter-to-receiver coupling criteria at each frequency point;
• separating the measured time signal into a first component and a second component including using a demodulation circuit where the measured time signal is separately multiplied by an amplitude-scaled version of the power signal at the first power level at the first frequency and the power signal at the second power level at the second frequency and each resulting signal is subsequently low-pass filtered to result in the first component and the second component;
• determining whether the second component meets the transmitter-to-receiver coupling criteria;
• and
• transmitting, from the antenna of the transmitter to a receiver, at the first power level and at one or more frequencies between the first frequency and the second frequency if the receiver is determined to be coupled based on the transmitter-to-receiver coupling criteria.

An apparatus comprising:

• a transmitter, including an antenna, wherein the transmitter is configured to transmit a superposition of a power signal at a first power level at a first frequency with a power signal at a second power level at a second frequency, wherein the power signal at the second power level is incremented in transmission frequency from a first value to a second value;
• and
• a controller configured to measure a time signal indicative of a transmitter-to-receiver coupling criteria at the antenna of the transmitter at each frequency point, separate the measured time signal into a first component and a second component by performing a frequency transform of the measured time signal and isolating a component of the measured time signal corresponding to a frequency band around the second frequency, and determine whether the second component meets the transmitter-to-receiver coupling criteria, wherein
• the transmitter is further configured to transmit, from the antenna of the transmitter, at the first power level and at one or more frequencies between the first frequency and the second frequency if the transmitter-to-receiver coupling criteria is met.

An apparatus comprising:

• a transmitter, including an antenna, wherein the transmitter is configured to transmit a superposition of a power signal at a first power level at a first frequency with a power signal at a second power level at a second frequency, wherein the power signal at the second power level is incremented in transmission frequency from a first value to a second value;
• and
• a controller configured to:
• measure a time signal indicative of a transmitter-to-receiver coupling criteria at the antenna of the transmitter at each frequency point,
• separate the measured time signal into a first component and a second component by using a demodulation circuit where the measured time signal is separately multiplied by an amplitude-scaled version of the power signal at the first power level at the first frequency and the power signal at the second power level at the second frequency and each resulting signal is subsequently low-pass filtered to result in the first component and the second component, and
• determine whether the second component meets the transmitter-to-receiver coupling criteria,
• wherein the transmitter is further configured to transmit, from the antenna of the transmitter, at the first power level and at one or more frequencies between the first frequency and the second frequency if the transmitter-to-receiver coupling criteria is met.